Blowing preventative for paper-machine felts



Oct. 18, 1932. l w. H. MlLLsPAuGH l 1,883,391

BLOWING PREVENTATIVE FOR PAPER MAGHINEJ'FELTS Filed Jari. 31. v19stPatented Oct. 18, 1932 orten STATES PATENT oFFicE WILLIAM H. MILLSPAUGH,OF SANDUSKY, OHIO, ASSIGNOB TO THE PAPER & TEXTILE MACHINERY COMPANY, OFSANDUSKY, OHIO, A CORPORATION OF OHIO `BLO'WING PREV-ENTATIVE FORPAPER-MACHINE IELTS Application led January 31, 1930. Serial No.424,795.

edects in connection with the deflection of peper-carrying elts.

ln n paper-melting machine, the imposition oi the paper sheet on atravelling felt will entrein air between the paper and felt, end whenthe felt is drown over or` in engagen ment with e deiocting roll thepressure effect on the felt and peper will compress the trapped eirwhich, forcing its way between the peper ond felt in advance of thepoint where the elt engages the roll, will cause the peper to pud or toleave the surface ol the felt. This effect, known as blowing, may besuciently pronounced to cause serious trouble in some ceses, especiallyin high speed machines.

Similar diiiiculty is encountered where top end bottom press ielts arebrought into coection by e, guideroll delecting the course of either orboth oi' the felis, in which case the peper sheet if cnrried by the feltengaging the roll may be blown from such felt as it approaches the roll,or the sheet if carried hy the other felt may be injured -by being blownagainst its own felt by air entreined end compressed between the papersheet and the telt in contact with the guide roll.

The object of the present invention is to prevent such blowingeiif`ects,lin connection with the deection of peper-carrying felts,V

by providing for escapement of the trapped nir. lThis is accomplished byutilizing e perforated hollow guide roll, interiorly open to theatmosphere, engaged by and deiecting the peper-carrying felt or one ofco-acting peper-carrying felts, whereby the oir trapped between thepaper and the felt in contact with the guide roll is forced out throughthe pores of the felt 'end the kperforartions or the deiiector roll tothe atmosphere. The dedector roil, suitably mounted to eiect e desireddeflection and thereby to-impose e pressure action against the tant feltand peper thereon may consist of e cylindrical shell having closelydrilled perfor-ations,

similar for example to an ordinary suctionroll shell, so as. to presenta large nuniber of closely disposed orifices for the escapement of theair.,

One illustrative embodiment of the invention is shown in the annexeddrnwing, in which: c

Fig. 1 diagrammatically represents a. po. er-machine press section;

4 ig. 2 is a detiil representation of a press felt and co-eotingperforated deecting roll. .ln the illustrated constructioi'i9 the papersheet l, received `from the wet end or other preceding section of themachine, is carried by the press felt 2 in contact with the top felt 3`between the cri-acting top end bottom prless rolls 4l and 5, sind isdelivered by the llhe press felt 2 is engaged by the perforated hollowguide .roll 6, which in this insteince is located to bring the 2o-actingfelts into co-action end to obtain n desired lap of the elts on the topress roll. By the pres'- sure imposed by tie deilecting roll againstthe elt and peper, the air trapped between the felt end peper over theroll is forced therefrom through the felt 2 into the erforations of theroll, thus escziping` to t e atmos here, A

l' in en arrangement of the type illustreted the paper sheet werecarried b the other felt thon that engaging the de ector roll, theperforations of seid roll would perzetion embodying the invention. litwlll be 'understood that the oreG-oing description with reference to thespecic embodiment selected for illustration is not to he teken aslimiting the invention, which is generally appliceble to end may be usedin various loca tions in machines of both the cylinder and n Fourdriniertypesor other types, end in machines for making either single-ply orplurally paper: For exemple, in n machine heving co-ecting felts tocarry the peper through the press, Aseparately formed peper sheets maybe imposed on the respective felis and brought into contact with onemother by the converging runs of the felts where they arp brought intoco-action by the deilector ro 1.

, What I claim as my invention, and desire n to secure by LettersPatent, is:

1. In a paper-making machine having co-l acting press rolls anda pair offelts co-acting to carry the aper between them throu h the press, a perorated hollow guide roll 1n` teriorly at atmospheric pressure and incontact with one of said elts, said guide roll beand deiiecting atcarried thereby suction consisting solely of a erforated holing locatedto bring the elts into' co-action -east one of said felts,

whereby only the pressure action imposed by said guide ,roll against thefelts and paper will cause air tra pcd or carried between the paper andt e felt in contact with said uide roll to be'pressed out through suchelt into the roll perforations and escape to the atmosphere.

2. In a paper-making machine embodying a paper-carrying felt, means forremoving air trapped betweeny the felt and pa er sheet without resort tot e use of low guide roll engaged by a deilecting the felt, the interiorof said roll bein always at atmospheric pressure, whereby on y thepressure action imposed by said roll against the felt and paper sheet isused to force the entrapped air through the pores of the felt andperforations of the roll to the atmosphere.

In testimony whereof, I have signed my name to this application. l

WILLIAM H. MILLSPAUGrH.

